*3.1.5 PNS manifestations*

Peripheral nervous system (PNS) presentations influence about 10 to 15% of NPSLE patients, and multiple concepts are taken into account in the late 1990s ACR-NPSLE patient descriptions. The greater part of patients present with peripheral neuropathy [40], which comprises mono-neuropathy, poly-neuropathy, cranialneuropathy, hyperinflammatory demyelinating poly-radiculoneuropathy, and plexopathy. A report noted that 17% of SLE-associated peripheral neuropathies are small-fiber neuropathy [41]. Small-fiber neuropathies are able to cause severe burning pain by targeting non-myelinated C fibers and finely myelinated A fibers. The diagnosis is verified via obtaining a cutaneous sample that exhibits injury to the dorsal root ganglia along with distal axons. The rest of the PNS presentations comprise autonomic disorders and myasthenia gravis [25].

## **3.2 Molecular mechanisms**
